Elevated levels of beta-chemokines in bronchoalveolar lavage fluid (BALF) of individuals infected with human T lymphotropic virus type-1 (HTLV-1)

Abstract

Pulmonary complications are known to develop in HTLV-1 carriers, including T lymphocytic alveolitis, and increased IL-2 receptor alpha (CD25)-bearing T cells have been found in BALF. Several chemokines may contribute to accumulation of T lymphocytes in the lungs of HTLV-1 carriers. Here, we compared the distribution of T lymphocyte subsets and beta-chemokines, such as macrophage inflammatory peptide-1alpha (MIP-1alpha), regulated on activation normal T expressed and secreted (RANTES), and macrophage chemoattractant protein-1 (MCP-1), in BALF and peripheral blood between HTLV-1 carriers and non-infected healthy normal subjects. Flow cytometric analysis with MoAbs to cell surface antigens was used to identify T lymphocyte subsets in BALF samples from HTLV-1 carriers (n = 13) and non-infected healthy controls (n = 10). The levels of different beta-chemokines were estimated by ELISA. High percentages of CD3+ cells, CD3 expressing HLA-DR antigen and CD3+CD25+ cells were detected in BALF of HTLV-1 carriers compared with non-infected controls. The concentration of MIP-1alpha in BALF of patients was significantly higher than in non-infected healthy controls and correlated well with the percentage of CD3+CD25+ cells. The level of RANTES in BALF was also significantly high in HTLV-1 carriers, but did not correlate with the percentage of CD3+CD25+ cells. On the other hand, the level of MCP-1 in BALF of HTLV-1 carriers was not different from that of controls. Our results suggest a possible interaction between activated T cells bearing CD25 and beta-chemokines, especially MIP-1alpha, which may contribute to the pulmonary involvement in HTLV-1 carriers.

Fig. 1

Concentrations of macrophage chemoattractant protein-1 (MCP-1), regulated on activation normal T expressed and secreted (RANTES) and macrophage inflammatory peptide-1α (MIP-1α) in BALF of HTLV-1 carriers and non-infected healthy volunteers. The whisker box plots represent 25th to 75th percent of result inside the box, the median is indicated by the horizontal bar across the box, and the whiskers on each box represent the 10th to 90th percentiles. **P < 0.01; *P < 0.05 (Mann–Whitney U-test); differences remained significant after correction for multiple testing using the Bonferroni method.

Fig. 2

Correlation between percentage of CD3⁺CD25⁺ cells and the concentration of macrophage inflammatory peptide-1α (MIP-1α) in the BALF of HTLV-1 carriers.